The man who spied on Cuba for the US
An unnamed US intelligence operative imprisoned in Cuba for 20 years has been freed in a high-level prisoner swap.
The unidentified Cuban male was exchanged for three Cuban prisoners held in the US. The three were named as part of a Florida-based spy ring knows as the "wasp network".
Though President Obama's administration has declined to name the US spy in Cuba, officials thanked him for his service and "critical assistance".
"This man, whose sacrifices were known only to a few, has spent nearly 20 years in a Cuban prison," the US Office of the Director of National Intelligence (ODNI) said in a statement on Wednesday.
"Information provided by this person was instrumental in the identification and disruption of several Cuban intelligence operatives in the United States and ultimately led to a series of successful federal espionage prosecutions," the agency added.
According to US officials, information the agent provided led to the identification and conviction of Defense Intelligence Agency senior analyst Ana Belen Montes. Montes spied on the US for Cuba for 17 years, passing secret messages about her national security colleagues.
Information garnered by the spy in Cuba also led to the prosecution of former state department official Walter Kendall Myers for conspiracy to commit espionage and wire fraud. His wife, Gwendolyn Myers, was jailed for conspiring to gather and transmit defence information.
The Wasp Network was also exposed as a result of the efforts of the US operative in Cuba, officials say.
A total of five members the network were found guilty in 2001 of conspiracy and failure to register as foreign agents in the US.
Cuba has maintained they posed no threat to the US and were only monitoring anti-communist exiles in Florida with the aim of preventing attacks by exiles on Cuba.
"In light of his sacrifice on behalf of the United States, securing his release from prison after 20 years - in a swap for three of the Cuban spies he helped put behind bars - is fitting closure to this Cold War chapter of US-Cuban relations," the ODNI spokesman concluded.